Functional alpha(1)-adrenergic receptor subtypes in human right gastroepiploic artery

AIM: To study the functional alpha(1)-adrenergic receptor (alpha(1)-AR) subtypes in human right gastroepiploic artery (RGA). METHODS: The effects Of alpha(2)-AR, alpha(1)-AR, and alpha(1)-AR subtype selective antagonists on norepinephrine (NE)induced vasoconstriction in isolated human RGA were observed by contractile function experiment. RESULTS: Cumulative concentration-response curves for NE were competitively antagonized in RGA by alpha(2)-AR selective antagonist yohimbine (pA(2) 6.82 +/- 0.28, slope 1.12 +/- 0.40), alpha(1)-AR selective antagonist prazosin (pA(2) 9.77 +/- 0.22, slope 0.90 +/- 0.22), alpha(1A)-AR selective antagonists RS17053 (pA(2) 8.42 +/- 0.20, slope 0.93 +/- 0.20) and 5-MU (pA(2) 8.42 +/- 0.22, slope 0.88 +/- 0.18), alpha(1D)-AR selective antagonist BMY7378 (pA(2) 6.84 +/- 0.32, slope 1.05 +/- 0.17), and alpha(1A)-, alpha(1B)-AR selective antagonist WB4101 (pA(2) 8.88 +/- 0.20, slope 1.15 +/- 0.16). The correlation coefficients between these pA2 values of alpha(1)-AR selective antagonists with pK(i) values of which obtained from alpha(1A)-, alpha(1B)- and alpha(1D)-AR cloned cells are 0.95, 0.82, and 0.42. After the vessels were pretreated by chlorethylclonidine (CEC), an alpha(1B)- and alpha(1D)-AR irreversible alkylating agent, the pD(2) values were changed from 5.9 +/- 0.5 to 5.6 +/- 0.6 and the maximal contraction was changed from (8.9 +/- 3.2) g to (8.0 +/- 3.2) g, respectively. The difference was not significant. CONCLUSION: In human RGA, the contraction response is mainly mediated by alpha(1)-AR, of which alpha(1A)-AR plays an important role, whereas alpha(1B)- and alpha(1D)-AR are not involved in the contraction response.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000182030200008&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Chemistry, MultidisciplinaryPharmacology & PharmacySCI(E)PubMed中国科学引文数据库(CSCD)3ARTICLE4327-3312